Perhaps it has occurred to you that we could tap Earth's magnetic field as a source of electrical potential from which we could then generate energy. One way to do this would be to spin a metal loop about an axis perpendicular to Earth's magnetic field. Suppose that the metal loop is a square that is 45.0 cm on each side and that we want to generate a potential in the loop of amplitude 125 V at a place where Earth's magnetic field is 0.50 x 10^-4 T. At what angular speed (in rev/s) would we have to spin the coil?